Place the black lentils in a sieve and wash under cold running water. Drain, place in a deep bowl and cover with cold water. Leave to soak for 10–12 hours.
Rinse the lentils then place in a saucepan with the measured boiling water. Bring to the boil, reduce the heat and simmer for 35–40 minutes or until tender. Drain and set aside.
Meanwhile, melt the butter in a large saucepan and add the onion, garlic, ginger and chillies. Stir-fry for 5–6 minutes and then add the turmeric, paprika, cumin, ground coriander, kidney beans and reserved lentils.
Add the measured water and bring the mixture to the boil. Reduce the heat and stir in the spinach. Cook gently for 10–15 minutes, stirring often. Remove from the heat and season with salt. Stir in the chopped fresh coriander and drizzle over the cream. Sprinkle over a little paprika and serve immediately in warmed bowls with hot Parathas (see